Automatic tuning system and apparatus



July ll 1939- A. A. coLLlNs 2,165,226

AUTMTIC TUNING SYSTEM AND Al-PARATUS I Filed Aug. 25, 1937 4 Sheets-Sheet l F Ll lllll- Illllllr @muv July 1l, 1939.

A. A. COLLINS AUTOMATIC TUNING SYSTEM AND APPARATUS 4 Sheets-Sheet 2 Filed Aug. 25. 1937 :fina-a5 l /l/ /lll INVENToR. www Q. @4J/662W),

ATTORNEY July 1l 1939- A. A.'co| L.|Ns 2,165,225A

AUTOMATIC TUNING SYSTEM AND APPARATUS Filed Aug. 25, 1957 4 Sheets-Sheet 3 IN VEN TOR.

' BY a ATTORNEY July 1l, 1939 A A. A. coLLlNs 2,165,225

AUTOIATIG TUNING SYSTEM AND APPARATUS Filed Aug. 25, l1937 4 Sheets-Sheet 4 INVENTOR.

' Y 6 ATTORNEY L Patented July .11, 1939 AUToMATlc TUNING SYSTEM AND APPARATUS l Arthur A. Collins,

Cedar Rapids, Iowa Application August 25', 1937, serial No. 160,920

12 Claims.

for actuating variable tuning devices and setting the same tuned to any one of a plurality of pre- -15 determined frequencies.

Another object of my invention is to provide means for simultaneously and automatically adjusting the tuning devices in a plurality of circuits, regardless of the relative angular position of the actuating shafts thereof, in corresponding tuned conditions.

Still another object of my invention is t0 provide means for automatically and simultaneously selecting in a plurality of tuning devices the particular frequency to which the several devices Will be automatically set, regardless of the relative angular position of the actuating shafts thereof at the selected frequency.

A further object of my invention is to provide mechanical shaft positioning means havingposivtive drive means operative in common with a plurality ofy shafts to establish the shafts in a home position, and individual drive means for each shaft for establishing the shafts respectively in selected positions.

A still further object of my invention is to provide a control circuit for automatic shaft positioning means ,which employs a minimum of parts and is simple in structure and operation.

Still another object of my invention is toprovide electrical control means for moving shaft positioning means to home position and for effecting selection of an operative position for the shaft, whereupon the control means is released and the shaft is moved tothe operative position by means individual thereto.

Another object of my invention is to provide a simplified electrical control system for shaft positioning mechanism whereby the shaft is moved to a home position and the mechanism is conditioned for establishing the shaft in a selected Other and further objects of my invention re- (Cl. 19a-142) side in the apparatus and yarrangements, hereinafter more fully set forth, with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a shaft positioning mechanism with portions of the casing broken away to show `the stop means and the shaft actuating means; Fig. 2 is a vertical longitudinal sectional view of the shaft positioning mechanism on an enlarged scale; Figs. 3, 4 and 5, are vertical cross-sectional views of the appa--A ratus taken on lines 3 3, 4-4 and 5 5 respectively, in Fig. 2; Fig. 6 is a vertical cross-sectional view taken substantially on line 6 6 in Fig'. 2, and showing the stop rings and the shaft rotated to home position, with a path cleared for movement ofthe selector stop; Figs. 7 and 8 are front elevational views of different types of panel arrangements of 'tuning elements with shaft positioning mechanisms mounted thereon and interconnected with electrical'control means indicated within the broken lines in Figs. 7 and 8 and shown in detail in Fig. '9, which is a schematic diagram of the circuits of the electrical control means employed in the system of my invention.

' The principal object of this invention is the automatic tuning of a radio transmitter or receiver having a plurality of tuning controls, so

that it may operate onva number of predeter-b' r mined frequencies. I will ldescribe the application of my invention specifically to a transmitter,-

quency, and some form of switching meansr for selecting the desired set of tuned circuits.- This system has practical limitations because of the -complexityof circuitconnections and switching apparatus which must be used in a multi-stage transmitter operating on more than two or threev frequencies.

'I'he arrangement'of my invention overcomes the practical difficulties inherent in previous systems, and, in addition, is-compact'and flexible in adjustment. This arrangement consists essen-l tially .of a system of mechanical positioning istA 30 ring carried by the shaft. Referring to the drawingsin more detail, refer- 45'support the series of stop rings Illa mechanisms applied to the rotating shafts of the adjustable tuning units of the transmitters, and

interconnected in such a way with suitable actuating means that a vgroup of dialed energy impulses -will act to position each o f the tuning shaftsto the desired angular position correspondving to the correct adjustment for each frequency. The angular position of each tuning shaft may be Vindependently predetermined for ten or more 'independent tuning adjustments, and a like numploys a positive drive from motive means toestablish the shaft in a home or start position, and

subsequently'allows spring means to act on an individual shaft to rotate the shaft to a desired operating position, and to maintain the shaft in 0 such position against a selector stopf -The shaft yactuating means are so constructed that a pluralityv of s hafts may be connected with a common motive means and rotated through different angular distances .in the operation'of the systemof 5 my invention. The electrical control means for actuating the shaft operates in a predetermined timed sequence, and includes means for moving a selector stop to any one of a plurality of positions for cooperation with a selected pre-set stop 35 denser, not shown. As illustrated more` particularly in Fig. 2, the shaft I is journaled in bearings 2, 3, mounted in the base structure I4 and bracket 5. The bracket 5 is supported by bolts 6, from the sector plate I -carried by the base structure 4.

o The shaft I carries a series of spacer rings 8 which are slidable but non-rotatable with respect tothe shaft because engaged by a key 9 which lies in a keyway Ia in shaft I. The spacer rings 8 have shoulders formed inl their outer edges which 107', so that each stop ring may be individually rotated with respect to adjacent non-rotatable spacer -Iings 4Ii without affecting the adjustments of others of the stop rings. The rings in the series Ina'. |07, coact individually with a movable selector stop I4.

The stop rings and spacer rings are clamped on the shaft I between a nut I5 and a collar I6 which maybe integral with the shaft I or rigidly 55 pinned thereto as by tapered 4pini 'I. The movable o lthereon in engagement with a driving gear 2| connected with a drive shaft 2 3 passingthrough bearings in the base 4. Suitable movement of shaft 23 therefore will position the selector stop I4 opposite any one of the stop rings Ilia I81`;

65 for coaction therewith to determine the angular position of the shaft I. "f'

In order that the movable selector stop I4 may l lbe shifted from one position to another, the shaft I is vmoved, to a home position as-shown in 'I8 Fig. 6, with the stop rings displaced to provide a clear p ath vfor the movable stop I4. 'Ihe mechanism for shifting the shaft I includesa ange I6a on the collar I6, which has an arcuate slot- I6b therein extending substantially 180 or Il slightly greater, vas illustrated particularly in Fig. 3. djacent the flangev I6a is a gear 24 rotatably mounted on the shaft I and carrying a pin 25 engaged in the slot I6b. Gear 24 is adapted to be driven by a rack 26 mounted in operative position inengagement with the gear 24, the rack 26 being moved in each operation a suilicient distance to rotate the gear 24 through substantially The operation of the shifting mechanism therefore is as follows. Considering the set position of the shaft I as shown in Fig. 3, gear 24 is rotated in a counterclockwise direction, the pin 25 eventually engages the end of s lot I6b and rotatesfthe collar I6 and shaft I with the gear 24 to the limit of movement thereof, as indicated in Fig. 6. With the shaft in this position th'e selector stop is movedto the desired location, and gear 24 is driven in reverse or clockwise direction to the limt.of its movement, .with pin 25 free to move in slot I6b.

The shaft I has individual means for moving it in clockwise rotation, comprisinga spiral spring element 21, shown vparticularly in Fig. 4, which is fixed to the shaft I and a pin 28 mounted on the base 4, as shown in Figs. 1 and 2. A washer 2'9 is provided between the gear 24 and spring 21.

IWith the shaft I in home position'the spring 21 is tensioned so that as the gear 24 is rotated clockwise the shaft follows under the action of spring 21 until the selector stop I4 is engaged by one of the stop rings, as indicated in Fig. 5. The gear 24 in the meantime continues to rotate to its fulllimit of movement, with pin 25 moving in slot I6b. SpringZ'I has sufficient tension at all times to maintain the shaft positively in selected position with the coacting stop ring in 'Y forced abutment with the selector stop I4.

Manual control knob 30, with d ial andindicator. is provided to facilitate adjustment of the stop rings in the automatic control mechanism in the arrangement thereof providing for selection of `a desired position for shaft I.

The shaft positioning mechanism of my invenf motor 3I and solenoid 32, as shown inr Fig. 9.

Fig. 8 shows a modified arrangement for conjoint operation of a number of units A, B, C. In the form shown in Fig. 8, the racks are combined in a single gear 26 which is mounted on the panel structure.

The solenoid 32 and spring 34 action is especially adapted for operation in contuate a rack 35, or any other suitable means, for

rotating the gear 26 as required.

Referring vnow to Fig. 9 lthe control system cludes an impulse dial switch 36, having impulse contacts 36a and off-normal contacts 36h; a minor switch 31 having actuating coil 38, release coil 39, and off-normal contacts at 48; a drum switch 4I; a'double wound timing relay 4 2; and

contacts at 43 actuated by the solenoid 32. A

solenoid actuated mechanism to avoid mechanical shock inthe operation of the system.

Actuating coil 38 of the minor switch 3'I is coni necte'd with one side 0f the source 4 5 through lead 4'I, and the circuit is completed through the impulse contacts 36a of dial switch 36 back to the other side of the source through lead 48. The

release coil 39 Yis connected through lead 41 to one side of the source 45, and the circuit is completed through relay contacts 42a, solenoid switch and 42"', either of which serves to actuate the contacts 42a, b and c. In addition the relay is a timing device operating with a slow release charactenstlc for properly controlling the circuits and the operation of the system. Windings 42'v and 42" are connected directly to the source 45 through lead 49. The circuit to winding 42 is completed through off-normal contacts 38h of the dial switch 36 in the initial operation of the system. Windings 42' and 42" are selectively connected through the drum switch 4| and minor switch 31, relay contacts 42c, off-normal minor switch contacts 40a. and and lead 48 back to the source 45. The drum switch 4| has two segmental contacts 50 and 5I connected respectively to windings 42' and 42", either segmental contact being connected in circuit depending upon the position of minor switch 31. An insulating segment 52 in drum switch 4| serves to disconnect both windings 42' and 42" when the drum switch, and associated drive shaft system 23,-are in corresponding position. As shown in Figs. 'i and 8, and indicated in Fig. 9, drum switch 4| is driven from'motor 3| by suitable gearing, and serves to establish the selector stop I4 in corresponding selected position for stopping the shaft I in desired position.

The motor 3 |v is reversible, and has the neutral lead 53 therefrom connected to one side of the source 45 through solenoid :switch contacts 43a' and lead 49. 'I'he forward and reverse leads are selectively connected back to the source 45 through the circuits above described for windings 42 and 42" of relay 42, the relay being operative during either forward or reverse operation of the motor 3|. Relayv 42 is maintained operative for a predetermined interval following cut-off of the source 45 in drum switch 4|, by reason of the slow release characteristic of the relay.

. Solenoid 36 is connected directlyto one side of the source 45 through lead 49, and the circuit is completed thereto through relay switch contacts 42h, off-normal minor switch contacts 40a and lead 48 back to the source 45. -A shunt circuitl for relay contacts 42b is provided through the solenoid switch contacts 43b So that the solenoid once operated is maintained operative until releaseof the minor switch 31 which opens onormal contacts 40a.

Solenoid switch contacts 43e and .off-normal;

l minor switch contacts 40h are connected in series with the'transmiter standby circuit to remove plate power from the transmitter during frequency changes with the apparatus of my invention.

Operation The sequence of operation of the automatic control `system of my inventionjis as follows, beginning with the transmitter in an operating condition on the frequency corresponding to,

say #4 and it is desired to operate on the fre-' Yshafts to home positions.

ation` of rlay 42 breaks circuit to release coil 39 at contacts 42a for the duration of the time 'that relay 42 is energized.

Release of the operators nger allowsl the dial switch 36 to return to normal position producing seven current impulses which ilowthrough actuating' coil 38 and cause the contact arm of minor'switch 31 to come up to the seventh position, as shown dotted in Fig. 9. Contacts 4|Ia`v close as soon as the contact arm moves from the oft position, and the contacts 40h open. Return of dial switch 36 to the normal position breaksV the circuit to winding 42' of relay 42; however,

the release time of relay 42 is suicient to keep the relay momentarily operated.

Closing of contacts 40a completes two circuits: firstly, one through relay contacts 42h and rack 26 tomove the shaft I to home position;

Aand secondly, a circuit through relay contacts -solenoid 32, operating the solenoid and causing When solenoid 32 is energized, solenoid switch l contacts 43a are closed, completing a circuit through motor 3|, segment 59 of drum switch 4|, the seventh contact of drumswitch 4| and minor switch 31, and contacts 42c and 40a, tb drive motor 3| in a forward direction luntil insulating contact 52 comes opposite the seventh contact of drum switch 4|, breaking the motor circuit and the circuit `to relay winding 42'. Should the inertia of motor 3| and drum switch 4| carry insulating segment 52 beyond the seventh contact, the circuit is remade through contact segment 5| and the motor -3I is driven in reverse direction; simultaneously the relay winding 42" is energized. The slow release of relay 42 prevents opening of the relay contacts immeor winding 42", so that this reversal operation may be effected.

Motor 3| cornes to rest, and after a predeter.- mined time interval the relay contacts are released. Current is applied to release coil 39 through contacts 42a, 43h and 40a, returning switch 31 to "home position. Contacts 40a open, removing power from solenoid 32, which has been kept on through contacts 43h, and allowing rack 26 to return to its normal position under the action of spring 34. Contacts 42o are provided especially to remove power from the minor switch and drum switch circuit while minor switch arm is moving towards oil position, to prevent further operation of the motor 3| and relay The full cycle of operation ofA the automatic positioning system may bel described less specifically as follows: An impulse transmitter of the type commonly' used in dial telephone circuits is operated to send a series ofY impulses to a selector switch and simultaneously to actuate a slow release relay device. 'I'he relay operates to apply power to solenoid means for moving all Switch means operated by the solenoid applies power" to a motor vwhich vfunctions under the control of the selector switch to establish the selector stop in desired position.` 'I'he relay is kept operativewith the .motor, and releases after a predetermined interval following disconnection` of the motor and the diately upon the disconnection of winding 42', y

relay. Release of the relay energizes release means for the selector switch, and power is re- ,of rotation permits simplification of the control system to a marked degree. In consequence, the

system of my invention employs a minimumiof. parts and is reliable and stable in operation.

Thus while I. have disclosed my invention in certain preferred forms, I intend no limitations thereon, except as may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A mechanical shaft positioning system including a series ofl stop rings disposed axially on a shaft, a movable stop selectively adjusted for engagement with one of the stop rings, spring Ameans connected with the shaft for urging said one of the stop rings in contact with said stop, and' positive drive means formoving said shaft with said stop rings to .a home position.

. 2. A mechanical shaft, positioning system in' cluding a series of stop rings disposed axially on a shaft, a movable stop selectively adjusted for engagement with one of the stop rings, spring means for urging said onev of the stop rings lin contactfwith said stop, and pin and groove drive means operable to move said shaft in opposition to said spring means to a predetermined home position, the groove feature of the last' said means being adapted to permit said shaft to stop in a l plurality of positions as determinedby said stop rings.

3. In a mechanical shaft positioning system including a series of stop rings disposed axially on a shaft, a movable stop selectively adjusted for engagement with one of the stop rings, a

flanged collar member mounted in fixed relation. on said shaft, a gear rotatively mounted on said shaft adjacent said collar member, pin and v arcuate groove connection means between said gear and said flanged collar member, and means for rotating said gear through an angular movement substantially equal to said arcuate groove.

4. In .a mechanical shaft positioning system including a series of stop rings disposed axially .on a shaft, a movable stop selectively adjusted for engagement with one of the stop rings, a spiral spring member mounted on said shaft and operative to urge the said one of the stop rings in contact with said stop, and positive drive means for moving said shaft with'said vstop ringsv to a home position and for tensioning said spring member for opperation to the opposite limit of movement. of said shaft.-

5. In a shaft positioning system, an assembly and spring means for rotating said assembly to bring the selected stop.ring' intoi contact with the stop, said solenoid actuated meansv being controlli so constructed and arranged 'as to permit various stopped positions of said assembly.

6. In a shaft positioning system, an assemblyv comprising a series of stop rings vdisposed axially onl a shaft, a movable stop adapted for coaction with a selected one of said stop rings, solenoid actuated means for rotating said assembly to a home position, motor means for setting said stop in alignment with the selected stop ring,

spring means for rotating said assembly to bring the selected stop ring into contact with the stop, said solenoid actuated means being so constructed and arranged'as to permit various stopped positions `of said assembly, and automatic electrical control means connected with said solenoid actuated means and said motor means and operable in a predetermined sequence for effecting establishment of the shaft in desired position.

7. In a shaft positioning system as set forthk .in claim 6, an impulse dial switch, and means vstop means adjustably mounted on a shaft, a

.movable stop adapted for coaction with a selected one of said stop means, means for separately rotating said shaft and moving said stop, and an automatic electrical control system including a time delay slow release relay device vfor directly controlling the operation of the last said means in a predetermined sequencer of operations toestablish the shaft in desired position. l

9. In a shaft positioning system, a plurality of stop means adjustably mounted on a shaft, a

movable stop adapted for coaction with a selected one of said stop means, means for separatelyy rotating said shaftv and moving said stop, and an automatic electrical control system including a time delay slow release relay device for directly the operation of the last said means, and switch meansactuated by the shaft rotating means for conditioning the stopmoving means and being cooperativev with said relay device for operating said shaft andJsaid-stop in a predetermined sequence of `operations to establish the shaft in desired position.

'said sourceto said relay through said off-normal contacts, connections from `said source to said solenoid means through contacts of said relay,

yconnections from said 'source -to said motor means through other ,contacts of said relay and said switch elements actuated by said solenoid means, the llastl said connections'including said selector switch and said drum switch for controlling the selective operation of said motormeans, and power .cut-off means connected with said source through other contacts of saidv relay and actuated upon the1 release of said relay after a predetermined period of operation thereof for removing power from said automatic control means,

including said cut-off means.

11. In a shaft positioning system, automatic electrical control means as described in claim 10 and including additional switch elements actuated by said solenoid means and connected in shuntl with the contacts o f said relay in circuit with said solenoid means, whereby said solenoid electrical control means as described in claim 10, and wherein said motor means isl provided with lseparate connections for forward andreverse operation, and said relay is provided with dual actuating windings connected for operation separately with the forward and reverse connections in said motor means.

ARTHUR. A. COLLINS.. 

